>Wiki N Islam at 07:32, 7 October 2021

2021-10-07T07:32:19Z

New page

{{redirect|Swatch of No Ground|the marine wildlife sanctuary at the same place|Swatch of No Ground Marine Protected Area}}
The '''Bengal Fan''', also known as the '''Ganges Fan''', is the largest [[submarine fan]] on Earth. The fan is about {{convert|3000|km|mi|abbr=on}} long, {{convert|1430|km|mi|abbr=on}} wide with a maximum thickness of {{convert|16.5|km|mi|abbr=on}}.<ref>{{cite journal | author=Shanmugam, G. | title=Submarine fans: A critical retrospective (1950–2015) | year=2016 | journal=Journal of Palaeogeography | volume=5 | issue=2 | pages=110–184 | doi=10.1016/j.jop.2015.08.011 | bibcode=2016JPalG...5..110S | doi-access=free }}</ref> The fan resulted from the uplift and erosion of the [[Himalayas]] and the [[Tibetan Plateau]] produced by the collision between the [[Indian Plate]] and the [[Eurasian Plate]]. Most of the sediment is supplied by the [[Ganges]] and [[Brahmaputra]] rivers which supply the Lower [[Meghna River|Meghna]] [[Ganges Delta|delta]] in [[Bangladesh]] and the [[Hooghly River|Hoogly]] delta in [[West Bengal]] (India). Several other large rivers in Bangladesh and India provide smaller contributions.<ref name=mpgCurray>{{cite journal|last=Curray|first=Joseph R.|author2=Frans J. Emmel|author3=David G. Moore|title=The Bengal Fan: morphology, geometry, stratigraphy, history and processes|journal=[[Marine and Petroleum Geology]]|date=December 2002|volume=19|issue=10|pages=1191–1223|doi=10.1016/S0264-8172(03)00035-7|publisher=Elsevier Science Ltd}}</ref> [[Turbidity current]]s have transported the sediment through a series of [[submarine canyons]], some of which are more than 1,500 miles (2,414 km) in length, to be deposited in the [[Bay of Bengal]] up to 30 degrees [[latitude]] from where it began. To date, the oldest sediments recovered from the Bengal fan are from [[Early Miocene]] age.<ref name=mpgCochran>{{cite journal|last=Cochran|first=J.R.|author2=Stow, D.A.V.|title=116 Initial Reports Table of Contents|journal=Proc. ODP, Init. Repts.|year=1989|volume=116|doi=10.2973/odp.proc.ir.116.1989|publisher=Ocean Drilling Program College Station, TX |display-authors=etal|series=Proceedings of the Ocean Drilling Program|editor1-last=Cochran|editor1-first=J.R|editor2-last=Stow|editor2-first=D.A.V}}</ref> Their mineralogical and geochemical characteristics allow to identify their Himalayan origin and demonstrate that the [[Himalaya]] was already a major mountain range 20 million years ago.<ref name=mpgFrance-Lanord>{{cite journal|last=France-Lanord|first=Christian|author2=Derry L.|author3=Michard A.|title=Evolution of the Himalaya since Miocene time: isotopic and sedimentological evidence from the Bengal Fan|journal=Geological Society Special Publication|year=1993|volume=74|issue=1|pages=603–621|doi=10.1144/GSL.SP.1993.074.01.40|bibcode=1993GSLSP..74..603F|url=https://hal.archives-ouvertes.fr/hal-02153142/file/Oxford%202.0%20complete%20rev.pdf}}</ref>

The fan completely covers the floor of the Bay of Bengal.<ref name=sepm92/> It is bordered to the west by the continental slope of eastern India, to the north by the continental slope of Bangladesh and to east by the northern part of [[Sunda Trench]] off [[Myanmar]] and the [[Andaman Islands]], the [[accretionary wedge]] associated with [[subduction]] of the [[Indo-Australian Plate]] beneath the [[Sunda Plate]] and continues along the west side of the [[Ninety East Ridge]].<ref name=sepm92>{{cite book|title=SEPM Special Publication, No. 92. External Controls on Deep-Water Depositional Systems|year=2009|publisher=SEPM ([[Society for Sedimentary Geology]])|isbn=978-1-56576-136-0|pages=107–131|author=Tilmann Schwenk|author2=Volkhard Spiess|chapter=Architecture and Stratigraphy of the Bengal Fan as Response to Tectonic and Climate Revealed from High-Resolution Seismic Data}}</ref><ref name=whoi-bf-mar2000/> The Nicobar Fan, another lobe of the fan, lies east of the Ninety East Ridge.<ref name=whoi-bf-mar2000/>

The fan was first identified by bathymetric survey in the sixties by Bruce C. Heezen and Marie Tharp which identified the abyssal cone and canyon structures. It was delineated and named by Joseph Curray and David Moore following a geological and geophysical survey in 1968.<ref name=whoi-bf-mar2000>{{cite web|last=France-Lanord|first=Christian|title=Summary on the Bengal Fan: An introduction to a drilling proposal|url=http://www.whoi.edu/pclift/BengalSummary.pdf|publisher=Woods Hole Oceanographic Institution|author2=Volkhard Spiess|author3=Peter Molnar|author4=Joseph R. Curray|date=March 2000}}</ref><ref name=curray1971>{{cite journal|last=Curray|first=Joseph R.|author2=David G. Moore|title=Growth of the Bengal Deep-Sea Fan and Denudation in the Himalayas|journal=Geological Society of America Bulletin|date=March 1971|volume=82|issue=3|pages=563–572|doi=10.1130/0016-7606(1971)82[563:GOTBDF]2.0.CO;2|bibcode=1971GSAB...82..563C}}</ref>

A deep sea canyon called '''Swatch of No Ground''' is located south of [[Sundarbans National Park]] and the island of [[Dublar Char]]. This area hosts important habitats for cetaceans including endangered species such as various [[dolphin]]s, [[Irrawaddy dolphin]]s, and [[Bryde's whale]]s (see [[Sundarbans National Park]]).

==References==
{{reflist}}

==Further reading==
*{{cite journal|last=Bastia|first=Rabi|author2=Suman Das|author3=M. Radhakrishna|title=Pre- and post-collisional depositional history in the upper and middle Bengal fan and evaluation of deepwater reservoir potential along the northeast Continental Margin of India|journal=Marine and Petroleum Geology|date=October 2010|volume=27|issue=10|pages=2051–2061|doi=10.1016/j.marpetgeo.2010.04.007}}
*{{cite journal|last=Subrahmanyam|first=V.|author2=K. S. Krishna|author3=M. V. Ramana|author4=K. S. R. Murthy|title=Marine geophysical investigations across the submarine canyon (Swatch-of-No-Ground), northern Bay of Bengal|journal=Current Science|year=2008|volume=94|issue=4|pages=507–513|url=https://www.researchgate.net/publication/27667740|publisher=Indian Academy of Sciences}}

{{Coord|12|N|87|E|display=title}}

{{Waters of South Asia}}

[[Category:Ganges]]
[[Category:Sediments]]
[[Category:Landforms of Bangladesh]]
[[Category:Landforms of India]]
[[Category:Landforms of Asia]]

Bengal Fan - Revision history

>Wiki N Islam at 07:32, 7 October 2021